petergriff but I'm still not entirely sure what they're so afraid of.
Political pressure. The government regulates banks.
A faction on the left believes that ALL porn is exploitive and non-consensual and contributes to sex trafficking; also, even when it's not, it is a slippery slope that leads to exploitation and other evils.
A faction on the right, mostly religious zealots, largely agree with those on the left PLUS believe that porn is a sin the same way that sex outside of marriage is a sin.
These groups can put enough pressure on elected officials to get the elected officials to pressure the regulators to pressure the banks to stop doing business with sex-related businesses.
It wouldn't be hard to track money from truly illegal sex work to a porn website to a bank. And with many laws, the standard to create a conspiracy is "knew or should have known."
And when making decisions about enforcing regulations, government regulators are usually subject to a "substantial evidence" standard, essentially meaning that if there is any evidence to support their decision, a court will uphold it.
So, if a website has content on it that appears to be illegal or might be illegal, it might not be too hard to convince banking regulators that a bank "should have known" they were taking money from illegal activities--and the regulators could potentially fine the bank big time.
If the bank attempts to overturn that in court, the regulators can point to the videos as substantial evidence. The only way a bank MIGHT overcome that would be to get all the actors in the videos in question to testify that everything was 100% consensual, that the drugs were fake, etc. etc.
And what do you think the odds would be of a bank being able to get all the actors in dozens of videos from around the world to come to the USA and testify? Even if they could, would they want to go through all that trouble?
It's much easier to put in strict prohibitions on the type of content that a website can show.
As much as I'm against this type of censorship, I would do the exact same thing if I were SLR. Any other choice would eventually lead to the demise of this great website. Or a vast reduction in the profitability, which would lead to people losing their jobs, and eventually result in less and lower quality content.